[systemd-devel] Masking mount units

[Lennart Poettering]

On Do, 31.10.24 12:08, Dan Nicholson (dbn at endlessos.org) wrote:

> On Thu, Oct 31, 2024 at 10:23 AM Lennart Poettering
> <lennart at poettering.net> wrote:
> >
> > On Do, 31.10.24 09:03, Phillip Susi (phill at thesusis.net) wrote:
> >
> > > Lennart Poettering <lennart at poettering.net> writes:
> > >
> > > Yes, but then it reads the disk and auto mounts a partition just because
> > > someone ran parted print.  Printing the partition table should not
> > > trigger auto mount.
> >
> > NO!
> >
> > I don't know parted, but why would it open device for *WRITE* if it
> > only wants to show contents of it? It should open it for *READ* then,
> > and thus not trigger any events.
>
> I'm reading between the lines a bit, but my guess is that libparted
> always opens the device writable in case you start issuing actual
> partitioning commands.

That sounds like a bug though. They should open the device for write
only when they need to make changes.

> To support "parted print doesn't trigger udev
> events", I think you'd have to change libparted so that it opens the
> device for read first (potentially with a shared lock) and then
> reopens it for write (with an exclusive lock) when needed (e.g. when
> using the mkpart command in the interactive session). Without that, I
> think you're always going to need workarounds such as masking mount
> units.

Yeah, what you are proposing sounds like it is the way to go indeed,
if parted really is not doing this already right now.

Lennart

--
Lennart Poettering, Berlin